I'm talking about things that were long before DOS even existed.
At that time you didn't even have the tools to cut sprites from image in the first place. That's why it took a lot of time (and I was 12 years old and my dad was pretty far away from an engineer, that didn't help).
I'm not sure how that happened - in DOS you could copy things to the framebuffer. There were libraries like Allegro which came with a million features including sound/UI/sprite rendering/animation/effects etc. out of the box.
But anyways copying a sprite to a screen is not hard even if you don't use a single piece of foreign code - you can read in a BMP file and just copy it row-by-row to the screen.